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Shoulder Pain–All About Rotator CuffsShoulder Pain–All About Rotator Cuffs

Spring sports are in full swing right now, and with it, so are rotator cuff injuries. Don’t get me wrong, we love that the Mariners are off to a good start and are hosting Los Angeles this week, but it’s a sure sign that a wave of rotator cuff injuries are on their way from archery, baseball and tennis players.

So, what is a rotator cuff injury, how is it treated and how do you prevent it in the first place? We’ll answer each of these questions for you here one by one.

Tug-of-War–How The Rotator Cuff Works

Your shoulder is the most mobile joint in the body. The top of the humerus (long upper arm bone) has a ball on it that fits neatly into the shoulder. On its own, it would swing loosely whichever direction it was being pulled.

Instead, your arm is held stable by four muscles surrounding the top ball (glenohumeral joint), all pulling in different directions to keep it stable. To understand how this works, imagine a tug-of-war; the flag in the middle stays suspended in the air as long as both sides are pulling equally hard. If one side pulls less than the other, however, the flag moves. The same is true of the four muscles stabilizing your arm at the shoulder.

Those four muscles, abbreviated as S.I.T.S. make up the rotator cuff.


Abducts (pulls away from the body) and elevates the shoulder out to the side.


Rotates the arm out away from the body. (if your elbow is bent and tucked into your side this movement moves your hand further from your body)

Teres Minor

Externally rotates the arm out away from the body (same as infraspinatus) while helping hold the shoulder in place.


Sitting directly above the ribs, this muscle depresses the head of the humerus (the top ball part of the bone) so that it can move smoothly in the joint without grinding up against the bones and muscles that make up the socket.

Treating Injured Rotator Cuff Muscles

Rotator cuff injuries are classified as either acute tears or generative tears.

Acute tears are sudden injuries such as jerking a heavy item up too hard or catching yourself when you trip in a way that tears one of the four rotator cuff muscles.

Degenerative tears are more common. These are injuries caused by wear and tear on the tendons holding the rotator cuff muscles in place. While they are more common as we age, they primarily come from one of three different reasons:

Repetitive stress:

Performing the same shoulder movements over and over again can stress your rotator cuff muscles beyond what they can bear. Often, you see this cause for injury in baseball and tennis players

Lack of blood supply:

As we age, less blood is delivered to our rotator cuff tendons. Having a regular blood supply is essential for every part of the body to maintain itself. Blood both carries away dead cells and delivers nutrients needed to rebuild damaged tissue. Small daily damage that accrues over time with regular use builds up, and with stunted healing from a lack of blood, the recovery time is too slow to keep up with the regular wear.

Bone spurs:

Treating Injured Rotator Cuff MusclesBone overgrowth is common on the underside of the acromion bone. When we lift our arms, these spurs rub on the rotator cuff tendon, creating extra strain and potentially tearing it. The graphic to the right highlights the acromion bones.

Treatment for a rotator cuff injury can range between everything from simple bed rest to surgery.

Basic treatment for less severe injuries often includes:


Your doctor may suggest limiting overhead activities and being more proactive about resting your shoulder. A sling is sometimes used to keep the shoulder still, allowing it to heal.

Activity modification

This one is simple–if it hurts, don’t do it. Avoid movements that cause additional pain.

Anti-inflammatory medication

Drugs like naproxen and ibuprofen can reduce pain while lessening swelling.

Physical Therapy

Strengthening exercises must be performed to restore movement and return function to your shoulder. This includes different range of motion exercises as well as flexibility focused movements. Strengthening can both relieve pain and prevent further injury.

Injury Prevention

Baseball players take the spotlight for rotator cuff injuries. The excessive force placed on their shoulders, especially pitchers, frays the tendons over time. Throwing a small leather coated cork ball isn’t the only guilty party here, though. You can injure your rotator cuff muscles just reaching up to change a lightbulb.

The first sign of a rotator cuff injury, unfortunately, is pain; reaching out to put your jacket on, grabbing something from the back seat of your car or even just shaking hands with someone. If these hurt, there’s a good chance your rotator cuff is torn or frayed.

Injury prevention for the rotator cuffs, thankfully, is fairly straightforward.

Weightlifting and stability exercises can develop the muscles in your shoulder keeping it safely secured. Because your shoulder has more range of motion than any other joint in the body it is significantly more at risk to injury. Increasing the strength of the muscles responsible for keeping the joint stable decreases your chances of injury.

An effective preventative plan must include both strengthening the larger surrounding muscles of the shoulder while isolating the smaller S.I.T.S. muscles to ensure the entire shoulder is improved.

You don’t need to be Felix Hernandez for rotator cuff work to be important. Exercises and stability work benefits everyone no matter their age or level of activity.

If you’re in the Snohomish/King County area and need help getting a painful shoulder back into healthy shape, call Lilly Physical Therapy at (425) 224-2476.